Field of the Invention
The production of tabloid-style newspapers is usually accomplished by printing on normal full size travelling web, slitting this web down the center and then slitting each of these two webs so that four webs are produced. Each of the final webs is cut transversely and the resulting sheets stacked for folding only once to form a fold line only along the lefthand edge of the final product. Folding is performed by a separate folding apparatus in which a blade on a rotating cylinder creates the initial fold and pushes the folded edge into the nip of a pair of cooperating second fold rollers. One of the second fold rollers has a crusher strip mounted in the outer surface which is timed to coincide with entry of a folded edge between the fold rollers and effect permanent creasing. The roll that carries the crusher strip also has margin rings whose outer surfaces are contained in an imaginery cylinder containing the outer surface of the crusher strip. The surfaces of the margin rings and the crusher strip are knurled or roughened to provide a good grip on the paper being folded.
In the past, fold rollers having the crusher strip and margin rings have always required removal and replacement when a folder was being changed to accommodate the folding of a different size tabloid. This is a job that usually requires a full day to complete and is therefore expensive both in terms of the effort involved as well as in terms of the downtime of the folder.